U.S. patent application number 14/233442 was filed with the patent office on 2014-06-19 for tilting-segment radial bearing for a single-shaft turbomachine.
This patent application is currently assigned to SIEMENS AKTIENGESELLSCHAFT. The applicant listed for this patent is Frank Bockel, Bernadette Brahm, Diethelm Dettmar, Anna Christina Droschinski, Bernd Luneburg, Umit Mermertas, Jan Soggeberg, Marcel Stranger, Andreas Winkler. Invention is credited to Frank Bockel, Bernadette Brahm, Diethelm Dettmar, Anna Christina Droschinski, Bernd Luneburg, Umit Mermertas, Jan Soggeberg, Marcel Stranger, Andreas Winkler.
Application Number | 20140169955 14/233442 |
Document ID | / |
Family ID | 46354261 |
Filed Date | 2014-06-19 |
United States Patent
Application |
20140169955 |
Kind Code |
A1 |
Brahm; Bernadette ; et
al. |
June 19, 2014 |
TILTING-SEGMENT RADIAL BEARING FOR A SINGLE-SHAFT TURBOMACHINE
Abstract
A tilting-segment radial bearing for a single-shaft turbomachine
is provided, having a support ring, a tilting-segment mounting and
a tilting segment, which in the installed state of the
tilting-segment radial bearing is supported on the support ring
such as to be seated on top and be radially displaceable by the
tilting-segment mounting. The mounting has a preload device, by
means of which the tilting segment is preloaded in the direction
toward the shaft of the single-shaft turbomachine when the
operating rotational speed of the single-shaft turbomachine is
above a predetermined tilting-segment preload rotational speed,
such that the tilting segment can be radially moved without preload
when the operating rotational speed of the single-shaft
turbomachine is below the tilting-segment preload rotational
speed.
Inventors: |
Brahm; Bernadette; (Bochum,
DE) ; Bockel; Frank; (Hennef, DE) ; Dettmar;
Diethelm; (Wesel, DE) ; Droschinski; Anna
Christina; (Mulheim an der Ruhr, DE) ; Luneburg;
Bernd; (Mulheim an der Ruhr, DE) ; Mermertas;
Umit; (Mulheim an der Ruhr, DE) ; Soggeberg; Jan;
(Dorsten, DE) ; Stranger; Marcel; (Mulheim an der
Ruhr, DE) ; Winkler; Andreas; (Duisburg, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Brahm; Bernadette
Bockel; Frank
Dettmar; Diethelm
Droschinski; Anna Christina
Luneburg; Bernd
Mermertas; Umit
Soggeberg; Jan
Stranger; Marcel
Winkler; Andreas |
Bochum
Hennef
Wesel
Mulheim an der Ruhr
Mulheim an der Ruhr
Mulheim an der Ruhr
Dorsten
Mulheim an der Ruhr
Duisburg |
|
DE
DE
DE
DE
DE
DE
DE
DE
DE |
|
|
Assignee: |
SIEMENS AKTIENGESELLSCHAFT
Munich
DE
|
Family ID: |
46354261 |
Appl. No.: |
14/233442 |
Filed: |
June 15, 2012 |
PCT Filed: |
June 15, 2012 |
PCT NO: |
PCT/EP2012/061433 |
371 Date: |
January 17, 2014 |
Current U.S.
Class: |
415/174.1 |
Current CPC
Class: |
F16C 17/03 20130101;
F16C 2360/23 20130101; F01D 25/16 20130101; F16C 2360/00 20130101;
F16C 2229/00 20130101 |
Class at
Publication: |
415/174.1 |
International
Class: |
F01D 25/16 20060101
F01D025/16 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 20, 2011 |
EP |
11174611.1 |
Claims
1. A tilting-segment radial bearing for a single-shaft
turbomachine, comprising: a supporting ring, a tilting-segment
mount and a tilting segment which, in the installed state of the
tilting-segment radial bearing, is overhead and is supported
radially displaceably on the supporting ring by the tilting-segment
mount which has a prestressing device and a holding part with a
locking means, with a shank mounted radially displaceably on the
supporting ring and with a plate which projects on and is fastened
to the shank and on which the tilting segment can be supported
radially on the inside and the prestressing device can be supported
radially on the outside, the shank being secured in a limited
manner to the supporting ring radially on the inside by the locking
means in such a way that the tilting segment is supported on the
plate and is prestressed with a predetermined threshold prestress
by the prestressing device only when the operating rotational speed
of the single-shaft turbomachine is identical to a predetermined
tilting-segment prestress rotational speed, wherein, at all the
operating rotational speeds of the single-shaft turbomachine above
the tilting-segment prestress rotational speed, the tilting segment
is prestressed in the direction toward the shaft of the
single-shaft turbomachine by the prestressing device, and, at all
the operating rotational speeds of the single-shaft turbomachine
below the tilting-segment prestress rotational speed, the tilting
segment is moveable, prestress-free, radially.
2. The tilting-segment radial bearing as claimed in claim 1,
wherein the prestressing device is adapted such that, when the
single-shaft turbomachine is operating at an operating rotational
speed above the tilting-segment prestress rotational speed, the
prestress of the tilting segment increases with the operating
rotational speed of the single-shaft turbomachine.
3. The tilting-segment radial bearing as claimed in claim 2,
wherein the prestressing device comprises a cup spring which is
supported radially on the supporting ring and on the tilting
segment.
4. The tilting-segment radial bearing as claimed in claim 1,
wherein the radial movement of the tilting segment is limited
outwardly.
5. The tilting-segment radial bearing as claimed in claim 4,
wherein the plate comprises on its radially outer side, for butting
against the supporting ring, an abutment, by which the radial
movement of the tilting segment is limited outwardly.
6. The tilting-segment radial bearing as claimed in claim 1,
wherein the shank projects from the plate radially inward with a
projection which is in engagement with the tilting segment, so that
the tilting segment is mounted radially displaceably and fixedly in
the circumferential direction.
7. The tilting-segment radial bearing as claimed in claim 6,
wherein the tilting-segment mount comprises a holding pin, by means
of which the minimum radial position of the tilting-segment radial
bearing is limited such that the tilting segment does not come out
of engagement with the projection.
8. The tilting-segment radial bearing as claimed in claim 1,
wherein the holding part, during its radial displacement, is guided
radially on the supporting ring.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the US National Stage of International
Application No. PCT/EP2012/061433 filed Jun. 15, 2012, and claims
the benefit thereof. The International Application claims the
benefit of European Application No. EP11174611 filed Jul. 20, 2011.
All of the applications are incorporated by reference herein in
their entirety.
FIELD OF INVENTION
[0002] The invention relates to a tilting-segment radial bearing
for a single-shaft turbomachine.
BACKGROUND OF INVENTION
[0003] A turbomachine, such as, for example, a single-shaft
turbomachine, has a rotor with a shaft. What may be considered for
mounting the shaft is, inter alia, a tilting-segment radial bearing
in which the shaft can rotate about its axis. The tilting-segment
radial bearing usually has three or four tilting segments, a
distinction being made between lower and upper tilting segments.
The lower tilting segments bear the weight of the shaft, its weight
being diverted into a foundation via the lower tilting segments,
the supporting ring and the bearing housing. The upper tilting
segments, in the event of a fault, prevent the shaft from lifting
off from the lower tilting segments and have a vibration-damping
effect upon the shaft. The upper tilting segments either lie
loosely on the shaft or are pressed onto the shaft by means of
springs.
[0004] For lubrication and cooling, an oil flow is introduced
through the tilting segments into the sealing gap between the shaft
and the sliding surfaces of the tilting segments. When the shaft
rotates, a hydrodynamic oil film, on which the shaft "floats", is
formed. If imbalances occur during rotation, vibrations may arise.
If the upper tilting segments lie loosely on the shaft, only slight
vibration damping can emanate from them. Conventionally, for
vibration damping, the upper tilting segments are pressed onto the
shaft by means of springs. When the machine is shut down, the shaft
has to be rotated slowly in what is known as a turn mode, so that
it does not sag during cooling. In this turn mode and when the
machine is started up, however, there is the disadvantage that the
upper tilting segments press onto the shaft, since this may cause
damage to the sliding surfaces of the tilting segments and to the
surface of the shaft.
[0005] Furthermore, there can only be a small quantity of oil
flowing into the sealing gap, and therefore only insignificant
cooling occurs. Moreover, because of the poor sliding behavior in
the turn mode, high drive forces are required, with the result that
the efficiency of the machine decreases.
[0006] FR 2574503 A1 describes a hydrodynamic bearing in which a
fluid connected to a pressure chamber is located in the gap between
a shaft and a tilting segment, the pressure chamber exerting
pressure upon the tilting segment. Further bearings are described
in U.S. Pat. No. 3,497,276 A and DE 14 25 111 A1.
SUMMARY OF INVENTION
[0007] An object is to provide a tilting-segment radial bearing for
a single-shaft turbomachine, the tilting-segment radial bearing
allowing good vibration damping and being coolable effectively
during operation.
[0008] The tilting-segment radial bearing according to the
invention for a single-shaft turbomachine has a supporting ring, a
tilting-segment mount and a tilting segment which, in the installed
state of the tilting-segment radial bearing, is overhead and is
supported radially displaceably on the supporting ring by the
tilting-segment mount which has a prestressing device, by means of
which the tilting segment is prestressed in the direction toward
the shaft of the single-shaft turbomachine when the operating
rotational speed of the single-shaft turbomachine lies above a
predetermined tilting-segment prestress rotational speed, so that,
when the operating rotational speed of the single-shaft
turbomachine lies below the tilting-segment prestress rotational
speed, the tilting segment is moveable, prestress-free,
radially.
[0009] At a low rotational speed of the single-shaft turbomachine,
the distance of the shaft from the lower tilting segments is short
because a hydrodynamic oil film on which the shaft "floats" cannot
be formed. In this case, the tilting segment of the tilting-segment
radial bearing according to the invention lies only with its weight
on the shaft. When the rotational speed of the shaft is increased,
the hydrodynamic oil film is formed and lifts the shaft. When the
predetermined tilting-segment prestress rotational speed is
overshot, the shaft is at such a distance from the lower tilting
segments that the prestressing device of the tilting-segment radial
bearing according to the invention advantageously exerts pressure
upon the shaft via the tilting segment.
[0010] The prestressing device is preferably designed in such a way
that, when the single-shaft turbomachine is operating at an
operating rotational speed above the tilting-segment prestress
rotational speed, the prestress of the tilting segment increases
with the operating rotational speed of the single-shaft
turbomachine. The prestressing device preferably has a cup spring
which is supported radially on the supporting ring and on the
tilting segment. Furthermore, according to the invention, the
prestressing device is designed in such a way that the prestress of
the tilting segment has predetermined threshold prestress when the
single-shaft turbomachine is operating at the prestess rotational
speed. According to the invention, the tilting-segment mount has a
holding part with a locking means, with a shank mounted radially
displaceably on the supporting ring and with a plate, on which the
tilting segment is supported radially on the inside and the
prestressing device is supported radially on the outside, the shank
being secured in a limited manner to the supporting ring by the
locking means in such a way that the tilting segment is supported
on the plate and is prestressed with the threshold prestress by the
prestressing device when the operating rotational speed of the
single-shaft turbomachine is identical to the tilting-segment
prestress rotational speed.
[0011] Preferably, the radial movement of the tilting segment is
limited outwardly. Furthermore, the plate preferably has on its
radially outer side, for butting against the supporting ring, an
abutment, by which the radial movement of the tilting segment is
limited outwardly. Moreover, the shank preferably projects from the
plate radially inward with a projection which is in engagement with
the tilting segment, so that the tilting segment is mounted
radially displaceably and fixedly in the circumferential direction.
Preferably, the tilting-segment mount has a holding pin, by means
of which the minimum radial position of the tilting-segment radial
bearing is limited such that the tilting segment does not come out
of engagement with the projection. Furthermore, the holding part,
during its radial displacement, is preferably guided radially on
the supporting ring.
[0012] When the single-shaft turbomachine rotates at a rotational
speed below the tilting-segment prestress rotational speed, the
tilting segment of the tilting-segment radial bearing according to
the invention can advantageously, guided radially, move freely on
the projection of the shank. When the rotational speed of the
machine reaches the tilting-segment prestress rotational speed, a
force originating from the predetermined threshold prestress of the
cup spring advantageously acts in addition to the weight of the
tilting segment. Furthermore, vibrations of the shaft can
advantageously be damped by the cup spring.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] A preferred embodiment of the tilting-segment radial bearing
according to the invention is explained below by means of the
accompanying diagrammatic drawings in which:
[0014] FIG. 1 shows a cross section through the embodiment of the
tilting-segment radial bearing according to the invention with an
overhead tilting segment,
[0015] FIG. 2 shows a longitudinal section through the overhead
tilting segment of the embodiment.
DETAILED DESCRIPTION OF INVENTION
[0016] As is clear from FIGS. 1 and 2, a tilting-segment radial
bearing 1 has in its upper bearing half 2 a supporting ring 3, a
tilting segment 5 and a tilting-segment mount 4, by means of which
the tilting segment 5 is fastened to the supporting ring 3. Located
on the radial inside of the tilting segment 4 is the
tilting-segment sliding surface 6 which is a cylindrical surface,
the axis of rotation of which coincides with the machine axis in
the installed state. In the installed state, the tilting segment 5
lies on a shaft. The tilting segment 5 has, on the side facing away
from the tilting-segment sliding surface 6, a tilting-segment back
7 which is parallel to the tilting-segment sliding surface 6.
[0017] As is clear from FIGS. 1 and 2, the tilting-segment mount 4
has a holding part 8 of hollow form which is mounted radially
displaceably on the supporting ring 3 by means of a shank 9.
Furthermore, the holding part 8 has a plate 10 lying on the outside
in the axial direction and in the circumferential direction.
Moreover, the holding part 8 has, on the radially inner plate
inside 11, a projection 15, the inside of which forms in the axial
direction and in the circumferential direction a continuous surface
with the inside of the shank 9.
[0018] As is clear from FIGS. 1 and 2, a prestressing device 20 is
supported on the plate outside 12 facing away from the plate inside
11. The prestressing device 20 has a cup spring 22, a shim 23, a
shoe 16, a compensating washer 17 and a ring nut 13. The spring
force of the cup spring 22 is directed radially. The shim 23 bears
radially on the inside on the plate outside 12 and is arranged in
the axial direction on the shank 9. The cup spring 22 lies radially
on the inside on the shim 23 and is arranged in the axial direction
on the shank 9. The shoe 16 is introduced in a clearance in the
inside of the supporting ring 3, the shoe 16 bearing radially on
the inside against the cup spring 22. The compensating washer 17 is
introduced between the shoe 16 and the supporting ring 3. The ring
nut 13 is attached to the radially outer end of the shank 9 and
axially on the outside and is supported via a supporting washer 14
in an outer clearance of the supporting ring 3.
[0019] As is clear from FIGS. 1 and 2, the shoe 16 has an abutment
18, against which the plate 10 can butt during its radial movement,
so that the radial movement is limited outwardly. The shim 23 has a
longer axial extent than the cup spring 22 so as to form between
the cup spring 22 and the abutment 18 a cup-spring cavity 21 in
which the cup spring 22 can expand axially during compression.
[0020] As is clear from FIGS. 1 and 2, the projection 15 is in
engagement with the tilting segment 5 on the tilting-segment back
7, so that the tilting segment 5 is guided radially on the
projection 15. A thread 25, into which the lower end of a holding
pin 24 is introduced, is introduced in the tilting segment 5 on its
tilting-segment back 7. The holding pin 24 is guided through the
holding part 8 of hollow form and a hole plate 27 which is
supported on the outer end of the holding part 8. The holding pin
24 is provided on the outside of the hole plate 27 with a holding
nut 26, by means of which the holding pin 24 is supported on the
hole plate 27, so that the minimum radial position of the tilting
segment 5 is secured.
[0021] As is clear from FIGS. 1 and 2, the tilting segment 5 can
move in a manner guided radially on the projection 15 and only
under the influence of its weight. When the shaft rotates at the
tilting-segment prestress rotational speed, it "floats" on a
hydrodynamic film and the tilting segment 5 lying on the shaft
butts with its tilting-segment back 7 against the plate inside 11,
and a force originating from the threshold prestress, set by the
prestressing device 20, of the cup spring 22 acts upon the tilting
segment 5 in addition to the weight.
[0022] As is clear from FIGS. 1 and 2, an oil duct 28 is formed in
the cavity between the holding pin 24 and the holding part 8 and
issues in an oil plenum 29 formed in the tilting segment 5. An oil
outlet 30 is provided in the tilting-segment sliding surface 6 and
is connected to the oil plenum 29.
[0023] As is clear from FIG. 2, a radially oriented guide pin 19 is
provided in a hole of the plate 10 and of the abutment 18, so that
the holding part 8, during it radial displacement, is guided
radially on the supporting ring 3.
[0024] To preset the play of the tilting segments 5, the
tilting-segment radial bearing 1 is arranged on edge and a dummy
shaft is introduced into the tilting-segment radial bearing 1. The
desired threshold prestress is set via the thickness of the shim
17. The ring nut 13 is then screwed down as firmly as possible and
the holding nut 26 is tightened to an extent such that the tilting
segment 5 just avoids lying on the dummy shaft. In this
arrangement, the maximum play of the tilting segment 5 is measured,
and if the play does not comply with a mounting specification, the
thickness of the compensating washer 17 is adapted. The ring nut 13
is subsequently loosened to an extent such that the tilting segment
5 hangs with predetermined play above the shaft. This position of
the ring nut 13 is identified by a marking.
[0025] For the final setting of the play, after the tilting-segment
radial bearing 1 has been installed in a machine housing and the
shaft has been installed in the tilting-segment radial bearing, the
ring nut 13 is first screwed down as firmly as possible and the
maximum play is measured. If appropriate, the thickness of the
compensating washer 17 is adapted. The ring nut 13 is subsequently
loosened as far as the marking and the play is measured. The play
is adapted, where appropriate, by readjusting the ring nut 13.
Finally, the holding nut 26 is loosened to an extent such that the
tilting segment 5 lies loosely on the shaft, and the ring nut 13
and holding nut 26 are secured against rotation.
* * * * *